1. Field of the Invention
The invention relates to a halogen-free flame-retardant resin composition, a wire and a cable, and, in particular, to a halogen-free flame-retardant resin composition that a discoloration caused by an antioxidant is suppressed. The invention also relates to a wire and a cable using the resin composition as an insulation or a sheath.
2. Description of the Related Art
Conventionally, compositions in which a metal hydroxide such as magnesium hydroxide or aluminum hydroxide, etc., is added to a polyolefin-based resin are used as a halogen-free flame-retardant resin composition which does not contain a halide. An antioxidant is added to such compositions for the purpose of suppressing deterioration during a molding process and when used.
As the antioxidant, a phenolic antioxidant or an amine antioxidant which suppresses cleavage of polymer molecular chains caused by radical formation is generally used (see, e.g., JP-A-2009-199783 and JP-A-63-56544). The amine antioxidant itself has a hue of yellow or brown, etc., and is also likely to discolor when used, hence, the phenolic antioxidant which is relatively less likely to discolor is often used for compositions which is desired to be white or light color.